The invention relates to air filters, including for internal combustion engines, and more particularly to an air filter with a reinforced pressure tap.
Air filters are known in the prior art, and typically include a cylindrical housing having distally opposite axially ends, and a cylindrical main filter element in the housing, the main filter element having an annular sidewall with a hollow interior and extending between distally opposite axially ends. Air flows radially inwardly through the annular sidewall of the filter element into the hollow interior and then axially through the hollow interior and then exits the housing. An outlet tube extends from the air outlet of the housing and conducts air therefrom. The outlet tube has a sidewall with a pressure tap opening there through communicating between the interior and exterior of the outlet tube, for sensing pressure in the outlet tube, for measuring restriction or pressure drop across the filter element.
In continuing development efforts directed toward weight and/or cost reduction, metal components are increasingly being replaced by plastic components, including housings and/or outlet tubes. In molding air cleaner housings from plastic, it is economical to mold the fitting for the pressure sensor connector or restriction indicator integral with the housing. This eliminates the necessity of producing or purchasing a separate part and assembling it onto the housing. Such integrally molded plastic fitting tube is externally threaded for receiving a pressure sensor connector. In the case of metal air cleaner housings, the fitting is also metal, and is typically welded in place, and is inherently strong. A plastic integral fitting on a molded plastic air cleaner housing will not have the same strength as metal, and is more susceptible to breakage, e.g. due to impact or vibration fatigue.
The present invention addresses and solves the noted breakage problem in a plastic fitting tube extending from a plastic outlet tube of a plastic air filter housing. An internal reinforcement member is provided in the plastic fitting tube resisting breakage of the latter. The reinforcement member extends far enough into the plastic fitting tube to support it at the critical area where it meets the main body of the air cleaner housing. Molded reinforcement structure in the plastic housing is also provided.